Soudal Genius Gun Gap Filling Expanding Foam is a polyurethane expanding foam with a specially designed patented trigger mechanism ensuring precise dosage and removing the need for an additional gun. It is easy to use and can be operated with one hand. It is also re-usable up to 6 weeks later. The expansion of the foam makes it the ideal gap filler. The foam is an excellent thermal and acoustic insulator which bonds to practically all building materials such as brick, concrete, PVC, timber, insulation materials, pipes, cables, ducts, metals and many other plastics (except PP, PE, PTFE and silicones).